1. Field of the Invention
The present invention relates generally to a system for measuring the deflection of the rotating shaft of a rotating object, and, more particularly, to a system for measuring the deflection of a rotating shaft in a wireless manner, in which data about the deflection of the rotating shaft of the rotating object, particularly data about run-out and offset, measured through non-contact-type angle division using a wireless method is transmitted to a collection system and is then read, so that the installation and handling of the system can be facilitated and the run-out and offset of a large-size rotating shaft can be accurately and easily measured.
2. Description of the Related Art
In general, rotating objects require that run-out and offset are measured to inspect the extent of the wear of the cuter circumferential surface of a rotating shaft and the true roundness of the rotating shaft.
In particular, in order to inspect the extent of the wear of the outer circumferential surface and true roundness of a rotating shaft part that is used in an airplane engine or a power plant in the disassembly or inspection of precise aviation equipment or power plant equipment, the part to be inspected must be mounted onto turning equipment and then inspected using the turning equipment, or separate dedicated measurement equipment must be used.
Although a contact-type division device has been adopted and used to measurer the run-out and offset of a rotating shaft, this method has a defect in that slippage occurs during angle division, and thus accurate angle division is not achieved, with the result that error occurs. Meanwhile, a prior measurement method using non-contact-type displacement sensors has a defect in that great error occurs depending on the material of a measurement target object and an environment.
Furthermore, prior art angle division using a wired method and a prior art system for measuring run-out and offset have problems in that many work hours are required due to the setting work of installing sensors and data transmission lines, the range of application to parts is narrow, and the reliability of measurement cannot be achieved because noise is included in a transmitted signal value due to the long distance transmission of measured data using a plurality of transmission lines. In particular, they have a problem in that it is almost impossible to apply them to narrow areas and complicated structures.
A system for measuring the strain of a flywheel rotor, which was developed so as to overcome various types of defects and problems that occur in the prior art measurement of the run-out and offset of a rotating shaft, is disclosed in Korean Unexamined Patent Publication No. 10-2006-0003762.
The system for measuring the strain of a flywheel rotor, as shown in FIGS. 1 to 7, includes a telemetry system for transmitting strain data, measured by a strain sensor 4 attached to a flywheel system, to a remote control unit via wireless communication and measuring the strain of a flywheel rotor by processing and analyzing strain data using the monitoring software of the control unit. The telemetry system includes the strain sensor 4 for measuring strain data, a transmitter 2 for amplifying the data measured by the strain sensor 4 and transmitting the amplified data via wireless communication, a receiver for receiving wireless data from the transmitter 2, a control unit connected to the receiver and configured to process and determine transmission data, and a Personal Computer (PC) 1.
Furthermore, a flywheel rotor 3 includes the transmitter 2 of the telemetry system including a strain gauge, and an axis 2′. The transmitter 2 includes a Printed Circuit Board (PCB) 7 including a Wheatstone bridge circuit 10 required for the strain gauge sensor, an operational amplifier 11 for amplifying the analog signals of the Wheatstone bridge circuit 10, a MicroController Unit (MCU) 13 implemented using a single chip in which peripheral devices, including an analog-digital converter for converting the amplified analog signals of the operational amplifier 11 into digital signals, a microprocessor for processing the digital signals of the analog-digital converter and controlling external devices, memory, an input/output interface and a timer, are integrated together, a multiplexer 12 for handling multi-channel input, an Radio Frequency (RF) reception module 14 for transmitting data to a remote location, and a transmitting antenna 15; cylinder-type upper casing 5 and lower casing 6 fastened to each other by screws 10; a battery 8 for supplying power; and a rubber packing 9.
The receiver includes a receiving antenna 16 and receiving communication module 17 for receiving data from the transmitter 2, and an RS232C interface module 18 for transmitting data to the control unit in a serial manner.
Accordingly, the system for measuring the strain of a flywheel rotor has advantages in that the convenience of data collection can be improved, trouble shooting can be simply performed because the system have a structure smaller and simpler than that of a wired system, the manufacture of the system is simplified thanks to small-sized parts, and relatively inexpensive RF communication can be adopted.
However, the system for measuring the strain of a flywheel rotor has a problem in that the strain sensor 4 is of a contact type, so that slippage occurs at the time of angle division, with the result that accurate angle division cannot be performed, thereby causing the frequent occurrence of error.